Linear accelerators (LINACs) are useful tools for medical applications, such as radiation therapy and imaging, and industrial applications, such as radiography, cargo inspection and food sterilization. In some of these applications, beams of electrons accelerated by the LINAC are directed at the sample or object of interest for performing a procedure or for analysis. However, in many of these applications, it can be preferable to use x-rays to perform the procedure or analysis. These x-rays are generated by directing the electron beams from the LINAC at an x-ray emitting target.
Since a standing wave LINAC can be made smaller than a traveling wave LINAC, a standing wave LINAC can be preferable for medical applications due to space available for medical instruments and some mobile industrial applications. In some medical applications, x-rays of more than one energy band may be desirable for analysis or to perform a procedure, such as radiation therapy in which the ionizing x-ray radiation is used to control malignant cells as part of cancer treatment. A LINAC can be operated to generate alternating outputs of electrons of different energy ranges, which can be used to generate x-rays of different energy bands. However, the accelerating structure of a standing wave LINAC is generally configured to support only a limited number of allowed modes when the accelerator is operating efficiently, only one of which can accelerate a beam efficiently. It has been difficult to develop an instrument that can operate stably to output electrons at different energies at a sufficiently high dose rate of electrons for the desired applications.
Systems and methods are disclosed herein for a multi-energy operation of a standing wave LINAC.